Light emitting device having dual sealing resins

ABSTRACT

Provided is a light emitting device with improved light extracting efficiency and further higher heat releasing performance. A light emitting device includes a planar lead frame having a first lead and a second lead, and includes a light emitting element mounted on the first lead, a resin frame surrounding a periphery of the light emitting element, a first sealing resin filled in the inner side of the resin frame and sealing the light emitting element, and a second sealing resin covering the resin frame and the first sealing resin. Lower end of inner surface of the resin frame is arranged only on the first lead, and at an outside of the resin frame, and the second resin member covers at least a part of the first lead and the second lead. Of the back-surface of the first lead, a region directly under the blight emitting element is exposed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 14/855,030, filedSep. 15, 2015, which is a divisional of U.S. Ser. No. 14/228,767, filedMar. 28, 2014 (now U.S. Pat. No. 9,172,013), which claims priority toJapanese Patent Application No. 2013-073661, filed Mar. 29, 2013, andJapanese Patent Application No. 2014-059728, filed Mar. 24, 2014. Theentire disclosures of these applications are hereby incorporated hereinby reference.

BACKGROUND

1. Technical Field

The present disclosure relates to a light emitting device applicable,for example, to purposes such as an indicator, a lighting luminaire, adisplay, and a backlight light source for liquid crystal display.

2. Background Art

Light emitting devices using light emitting elements such as lightemitting diodes or laser diodes are employed in various fields such asgeneral lighting such as in-door lighting, on-vehicle lighting, andbacklight for liquid crystal displays. Requirements for higherperformance in those light emitting devices are growing daily, and lightemitting diodes of further higher output (higher luminance) and lowercost are demanded. Light emitting diodes in various color tones arerequired according to recent applications, and moreover, the range ofcolor tone is very narrowly limited. In some cases light emitting diodesare used in combination with lenses of secondary optical system, etc.,and light emitting diodes which have compatibility with lenses ofsecondary optical system are also required.

In order to realize white light emitting diodes, light emitting deviceswhich employ combinations of blue light emitting diodes and yellowfluorescent materials (for example, YAG fluorescent materials) have beenin use. This may be obtained by injecting a mixture of a resin and afluorescent material in a region where a light emitting element ismounted.

After mounting a light emitting element, the resin to seal the lightemitting element is generally injected in a recess where the lightemitting element is mounted. Such recess is formed by, for example,processing a recess in a lead frame, or defined in a resin package whichis integrally molded with a lead frame, etc., typically formed by way ofmold processing, so that recesses of a relatively uniform shape and sizecan be manufactured.

See Patent Literature 1: JP 2011-216875A.

See Patent Literature 2: JP 2012-504341A.

See Patent Literature 3: JP 2011-009298A.

However, a disadvantaged resin package type light emitting device whichis integrally molded with the lead frame may include a gap (P—N gap)which occurs between the lead frame components in its light emittingportion, which may result in absorption of light emitted from the lightemitting element at the P—N gap.

SUMMARY

The present invention is conceived in view of the above circumstances,and an object of the present invention is to provide a light emittingdevice which can provide further improvement in the light extractionefficiency and has higher heat dissipation efficiency.

In order to solve the problems described above, a light emitting deviceaccording to example embodiments of the present invention includes aplanar lead frame having a first lead and a second lead, and includes alight emitting element mounted on the first lead, a resin framesurrounding a periphery of the light emitting element, a first sealingresin filled in an inner side of the resin frame and sealing the lightemitting element, and a second sealing resin covering the resin frameand the first sealing resin. Lower end of inner surface of the resinframe is arranged only on the first lead, and at an outside of the resinframe, the second resin member respectively covers at least a portion ofthe first lead and at least a portion of the second lead. Of theback-surface of the first lead, a region directly under the lightemitting element is exposed.

Alight emitting device according to the disclosure can provide higherlight extraction efficiency and heat releasing property.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top view of a light emitting device using a molded resinmember according to an embodiment of the present invention, and FIG. 1Bis a cross-sectional view of FIG. 1A.

FIG. 2A is a top view of a light emitting device using a molded resinaccording to another embodiment of the present invention, and FIG. 2B isa cross-sectional view of FIG. 2A.

FIG. 3 is a schematic cross-sectional view of a light emitting deviceaccording to another embodiment of the present invention.

FIG. 4 is a process drawing showing an embodiment of a manufacturingstep of preparing a lead frame, in a light emitting device according toan embodiment, arranging a molded resin between the lead framecomponents.

FIG. 5 is a process drawing showing a manufacturing step of the lightemitting device according to an embodiment shown above, of arranging amolded resin between the lead frame components.

FIG. 6 is a process drawing showing a manufacturing step of the lightemitting device according to an embodiment shown above, of disposing alight emitting element on the lead frame, and the lead frame and thelight emitting element are electrically connected by way of wirebonding.

FIG. 7 is a process drawing showing a manufacturing step of the lightemitting device according to an embodiment shown above, of forming aresin frame on the lead frame.

FIG. 8 is a process drawing showing a manufacturing process of the lightemitting device according to an embodiment shown above, of forming afirst sealing resin by filling a sealing resin in the inner side of theresin frame and hardening.

FIG. 9 is a process drawing showing a manufacturing process of the lightemitting device according to an embodiment shown above, of forming asecond sealing resin to cover the first sealing resin.

FIG. 10 is a process drawing showing a manufacturing process ofpreparing a lead frame, in a light emitting device according to anembodiment, in which a molding resin member is not arranged between thelead frame components.

FIG. 11 is a process drawing showing a manufacturing process of thelight emitting device according to an embodiment shown above, ofmounting a light emitting element on the lead frame, and the lead frameand the light emitting element are electrically connected by way of wirebonding.

FIG. 12 is a process drawing showing a manufacturing process of thelight emitting device according to an embodiment shown above, of forminga resin frame on the lead frame.

FIG. 13 is a process drawing showing a manufacturing process of thelight emitting device according to an embodiment shown above, ofdisposing a first sealing resin by filling a sealing resin in the innerside of the resin frame and hardening.

FIG. 14 is a process drawing showing a manufacturing process of thelight emitting device according to an embodiment shown above, of forminga second sealing resin to cover the first sealing resin.

FIG. 15 is a perspective view showing an illustrative example of a lightemitting device according to an illustrative example of the presentinvention.

FIG. 16 is a perspective view showing an illustrative example of a lightemitting device according to an illustrative example of the presentinvention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present invention will be described in detail belowwith reference to the accompanying drawings. The embodiments areintended as illustrative of a light emitting device to give a concreteform to technical ideas of the present invention, and the scope of theinvention is not limited to those described below. The sizes, materials,shapes and the relative arrangements of the members described in theembodiments are given as an example and not as a limitation to the scopeof the invention unless specifically stated. The sizes and thepositional relationships of the members in each of the drawings areoccasionally shown exaggerated for ease of explanation. In thefollowing, terms indicating a specific direction or a position (forexample, “upper”, “below”, “right”, “left”, “front”, and “back” andother terms including those terms) may be used in the following when itis appropriate. But the use of these terms is for the ease ofunderstanding of the present invention with reference to theaccompanying drawings, and the scope of the present invention is not tobe limited by the commonly accepted definitions of such terms.

FIGS. 1A-B and 2A-B are schematic views each showing a light emittingdevice 1 according to example embodiments of the present invention. Thelight emitting device 1 according to the present embodiment includes, asshown in FIGS. 1A-B, 2A-B, a planar lead frame 2 which includes a firstlead 11 and a second lead 12. The light emitting device 1 includes alight emitting element 4 mounted on the first lead 11, a resin frame 3surrounding the periphery of the light emitting element 4, a firstsealing resin 5 which is filled in the resin frame 3 to seal the lightemitting element 4, and a second sealing resin 6 which covers the resinframe 3 and the first sealing resin 5. The lower end of the innersurface 20 of the resin frame 3 is arranged only on the first lead 11.The second sealing resin 6 covers, at outside of the resin frame 3, atleast a part of the first lead 11 and a part of the second lead 12. Ofthe back-surface of the first lead 11, a region directly under the lightemitting element 4 is exposed. In a technique to form a recess of alight emitting device by using a conventional mold processing, in orderto change the planar dimension and/or depth of the recess, a mold itselfis needed to be remodeled, so that the planar dimension, the depth, orthe like of the recess is not a flexible task But employing such a lightemitting device as described above allows adjustment of the planardimension, the depth, etc., of the light emitting devices. In thespecification, the term “light emitting portion” refers to a regionwhere a light emitting element is mounted on the lead frame and a resinwhich seals the light emitting element is disposed. In the presentspecification, the term “planar shape” is not intended to indicate aperfectly flat plate-shape, and may include a surface with minute uneventexture. A planar shape as a whole may be sufficient and, for example, asmoothness determined by arithmetic average roughness is notspecifically required.

Each constituent component of the light emitting device 1 according toexample embodiments of the present invention will be described in detailbelow.

(Resin Frame)

In the light emitting device 1 according to example embodiments of thepresent invention, the resin frame 3 is disposed surrounding theperiphery of the light emitting element 4 mounted on the first lead 11.The region surrounded by the resin frame 3 is filled with a sealingresin (first sealing resin 5) to form the light emitting portion. Theresin frame 3 is formed to surround the light emitting element 4, sothat the resin frame 3 serves to hold the sealing resin (uncured stateof the first sealing resin 5) within the light emitting portion. Theresin frame 3 is formed by arranging an uncured raw material of theresin frame 3 in a region to form the resin frame 3 in a desired shape,and hardening the raw material.

Examples of a light emitting portion of a light emitting device includea lead frame processed to define a recess, and a resin package which isintegrally molded with a lead frame, and those are formed, for example,by way of mold processing. Thus, in order to change the planardimension, the height, the width, etc., of the light emitting portion,the mold it self may be needed to be remade. Further, in the case ofprocessing a recess in a lead frame, a margin for pressing is needed atthe time of forming a recess, which may increase the size of the lightemitting device by the margin for pressing, or reduce the planardimension for the element mounting portion.

According to example embodiments of the present invention as describedabove, the resin frame 3 can be formed after mounting a light emittingelement on the lead frame, which can facilitate a design change of theplanar dimension, the height, the width, etc., of the light emittingportion. Thus, according to example embodiments of the presentinvention, light emitting devices of high productivity can be provided.

Also, according to example embodiments of the present invention, therecess is not defined in the lead frame by processing a mold, so that aneed for the margin for pressing can be eliminated, and thus the size ofthe light emitting device 1 can be reduced or the planar dimension ofthe light emitting portion can be increased by the width of the marginfor pressing. That is, in order to define a recess of the lead frame, amargin for pressing with a sufficient width is needed at the time ofpress-working. In the case of the light emitting device 1 according toexample embodiments of the present invention, a margin for pressing isnot needed. Accordingly, as described above, a reduction in the size ofthe light emitting device 1 or an increase in the planar dimension ofthe light emitting portion by the width of the margin for pressing canbe achieved.

In embodiments of the present invention, the lower end of the innersurface 20 of the resin frame 3 is may be arranged only on the firstlead 11. In the specification, the expression “the lower end of theinner surface 20 of the resin frame 3 is arranged only on the first lead11” refers that the entire lower end (the entire periphery of the lowerend) of the inner surface 20 of the resin frame 3 is located on thefirst lead 11 and is not present on the second lead 12. According to thestructure described above, the lower end of the inner surface 20 of theresin frame 3 is arranged only on the first lead 11, so that only thelead frame (first lead 11) having high reflectance is exposed at theinner side of the resin frame 3, and thus the light emitting efficiencyof the light emitting device can be improved.

In this case, the lower end of the outer surface 21 of the resin frame 3is not needed to be on the first lead 11 and may be present on thesecond lead 12, as long as the entire lower end of the inner surface 20of the resin frame 3 is formed on the first lead 11. The lower end ofthe outer surface 21 of the resin frame 3 may be located on the firstlead 11. For example, in the case where the molded resin 13 is arrangedbetween the first lead 11 and the second lead 12, the resin frame 3 canbe formed such that the lower end of the inner surface 20 of the resinframe 3 is arranged on the first lead 11 while the lower end of theouter surface 21 of the resin frame 3 is arranged on the molded resin 13or the second lead 12. On the other hand, in an embodiment where themolded resin 13 is not arranged between the first lead 11 and the secondlead 12, the absence of the molded resin 13 between the first lead 11and the second lead 12 may lead the resin frame 3 to flow out betweenthe first lead 11 and the second lead 12. Thus, both the lower end ofthe inner surface 20 of the resin frame 3 and the lower end of the outersurface 21 are preferably arranged on the first lead 11.

In one example frame insertion type light emitting device, a gap(hereinafter may referred to as a “P—N gap) between the lead framecomponents is located in the light emitting portion, which may result inabsorption of light emitted from the light emitting element 4 at the P—Ngap. Further, generally the light emitting element 4 is not mounted overthe P—N gap and which limits available locations for mounting the lightemitting element 4 in the light emitting device. However, in a lightemitting device according to example embodiments of the presentinvention, the lower end of the inner surface 20 of the resin frame 3 isarranged only on the first lead 11 and the P—N gap is not arranged inthe inner bottom surface of the resin frame 3. Thus, on the bottomsurface, the mounting location for the light emitting element 4 is notlimited and the light emitting element 4 can be mounted in the vicinityof the center of the light emitting device. With this arrangement, alight emitting device with further higher light extraction efficiencybecomes possible.

Also, in the case where both the lower end of the inner surface 20 andthe lower end of the outer surface 21 of the resin frame 3 are presentonly on the first lead 11 (that is in the case where the entirety of theresin frame 3 is arranged only on the first lead), detachment of theresin frame 3 due to the movements of the first lead 11 and the secondlead 12 in different directions, can be avoided. That is, for example,in the case where a molded resin 13 is disposed between the first lead11 and the second lead 12 and the resin frame 3 is arranged spanning thefirst lead 11 and the second lead 12, the first lead 11 and the secondlead 12 may be pulled in different directions due to the thermalexpansion of the second sealing resin (lens resin). In this case, theinterfaces of the resin frame 3 with the first lead 11 or the secondlead 12 may be subjected to forces in different direction, which mayresult in detachment of the resin frame 3 from the first lead 11 or thesecond lead 12 or the both. However, in the configuration describedabove, both the lower end 20 and the lower end of the outer surface 21of the resin frame 3 are located only on the first lead 11 (that is, theentirety of the resin frame 3 is arranged only on the first lead 11.Thus, a state in which the interfaces of the resin frame 3 with thefirst lead 11 or the second lead 12 may be subjected to force indifferent directions does not occur, so that probability of the resinframe 3 detaching from the lead frame (first lead 11) is extremely low.According to example embodiments of the present invention, the resinframe 3 is hardly detached from the lead frame (first lead 11), so thata light emitting device with high reliability can be provided.

In the light emitting device 1 according to example embodiments of thepresent invention, the resin frame 3 can be formed with any resin whichallows forming of the resin frame 3 in any desired shape and curingafter molding the frame. Examples of such a resin include athermosetting resin and a photosetting resin. In the case where athermosetting resin is used as a raw material of the resin frame 3, heatis applied to the raw material to cure the raw material, to form theresin frame 3. In the case where a photosetting resin is used as a rawmaterial of the resin frame 3, light is applied to the raw material tocure the raw material, to form the resin frame 3. Examples of the resinwhich constitutes the resin frame 3 include a silicone resin and anepoxy resin.

In the light emitting device 1 according to example embodiments of thepresent invention, in order to increase the reflectance of the lightfrom the light emitting element 4 to increase the light extractionefficiency, the resin frame 3 preferably contains a reflective membersuch as titanium oxide, aluminum oxide, zirconium oxide, or magnesiumoxide. Particularly, titanium oxide may be preferable. Containingtitanium oxide in the resin frame 3 allows for significantly highreflectance of light which allows for an improvement of the lightextracting efficiency.

In the light emitting device 1 according to example embodiments of thepresent invention, the light emitting portion is formed with the resinframe, which allows for formation of the light emitting portion in anydesirable shape. The resin frame 3 can be formed in various shapes, suchas a circular shape, an elliptical shape, a rectangular shape, or asquare shape, in a top view. Also, a polygonal shape such as a hexagonalshape or an octagonal shape, or a shape with rounded corners or a shapewith a planar curved surface may be employed. The shape of the resinframe 3 in a top view is not limited to those shown above, and anyappropriate shape may be employed.

The resin frame 3 includes, for example as shown in FIG. 1B and FIG. 2B,a curved inner surface 20 and a curved outer surface 21. The resin frame3 includes a protruded shape with a rounded tip in a cross section whichincludes the central axis of the resin frame 3. The resin frame 3 havinga curved inner surface 20 and a curved outer surface 21 can be formed byusing a syringe-like dispenser, supplying a raw material of the resinframe 3 on the lead frame 2 and curing.

The resin frame 3 may be disposed, as shown in FIG. 2B, in aperpendicular direction, or may be disposed, as shown in FIG. 1B,inclined inwardly of the resin frame 3 (that is, in a direction towardthe central axis of the resin frame 3). In the case where the innersurface 20 is formed inclined inwardly, for example, in the forming thesecond sealing resin, to be described below, at the time of transfermolding of the second sealing resin in a lens shape, the resin frame 3can be prevented from being in contact with the mold for the secondsealing resin 6. Further, the inner surface 20 is formed inclinedinwardly, so that the fluorescent material contained in the firstsealing resin 5 as the wavelength converting member can be suppressedfrom depositing on the resin frame 3, and accordingly, variance in thelight emission can be prevented.

The resin frame 3 may have a shape, as shown in FIG. 3, in a crosssection which includes the central axis of the resin frame 3, in which asemicircular part of a shape is connected to a circular shape, leavingconstricted parts at the connecting portions. In this case, the circularportion disposed on the semicircular portion is preferably at an innerside (toward the central axis of the resin frame 3) than thesemicircular portion. With this arrangement, in a similar manner asdescribed above, the resin frame 3 is prevented from being in contactwith the mold for the second sealing resin 6, which facilitates themanufacturing, and the fluorescent material is suppressed fromdepositing on the resin frame 3, and thus, variance in the lightemission can be prevented. The resin frame 3 having such a cross sectioncan be formed easily by disposing a first level of resin frame with apredetermined size on the first lead 11, and disposing a second level ofresin frame with a smaller diameter than the first level of the resinframe on the first level of the resin frame.

In this arrangement, in response to increasing demands for higher outputpower in the light emitting diodes, increasing the planar dimension ofthe light emitting portion where the light emitting element to bemounted to increase the light extraction efficiency is one solution.Also, reducing the depth of the recess of the resin injecting portionwhich contributes to a reduction of absorption of light in the housingsuch as molded resin, is also one solution to increase the lightextraction efficiency. In order to facilitate the combination of thelight emitting diodes and lenses of secondary optical system, decreasingthe planar dimension of the light emitting portion is one solution.Also, in order to efficiently manufacture light emitting diodes in anarrow range of color tone, the variation in the amount of thefluorescent material injected in the recess is needed to be reduced. Forthis, increasing the depth of the recess in the resin injecting portionis one solution to reduce the uneven distribution of the amount of thefluorescent material. As described above, the light emitting devices aredesigned to have, for example, optimum planar dimensions and depths ofthe light emitting portions respectively with respect to eachapplication, and various specifications are provided according to eachapplication.

However, a disadvantageous light emitting devices with resin packageswhich are made by mold processing require remodeling of the mold itselfto change the planar dimension of light emitting area and/or the depthof the recess of each type of light emitting devices. Changing the moldsto meet all those different specifications require labor and time, sothat flexible adjustments of the planar dimension and/or the depth ofthe light emitting portion have been unable to be achieved. In the lightemitting device according to example embodiments of the presentinvention, the light emitting element mounting portion is demarcated bythe recess, so that flexible adjustments of the planar dimensions andthe depths of the light emitting portions of the light emitting devicesbecome possible.

In the light emitting device 1 according to example embodiments of thepresent invention, the width and the length of the resin frame 3 aredetermined based on the planar dimension of the light emitting portion,the planar dimension which allows formation of the sealing resininjection portion, and the mechanical strength, etc., of the resin frame3. The width and the length of the resin frame 3 can be appropriatelyadjusted as long as sufficient planar dimensions for the light emittingportion and the sealing resin injecting portion can be secured, and alsothe mechanical strength of the resin frame 3 can be secured.

The height of the resin frame 3 is determined based on, for example, themechanical strength of the resin frame 3 and the range of color tonedesired for the light emitting device 1. The height of the resin frame 3can be appropriately adjusted as long as sufficient mechanical strengthof the resin frame 3 can be secured and the desired range of color tonecan be securely provided.

(Lead Frame)

In the light emitting device 1 according to example embodiments, thelead frame 2 includes a pair of first lead 11 and second lead 12 and maybe electrically connected to one or a plurality of elements mounted onthe first lead 11. Thus, the lead frame 2 supplies electricity to thelight emitting element 4, etc., and also serves as the portion to mountthe light emitting element 4, etc. (The term “element” used in theembodiments includes a light emitting element 4, and in the case wherethe light emitting device 1 includes a protective element 7, it alsoincludes the protective element 7. The elements which includes the lightemitting element 4 and the protective element 7 may be referred to as“light emitting elements 4, etc”.)

The material of the lead frame 2 is not specifically limited as long asit can serve for mounting the light emitting element 4, and as theelectrodes of the light emitting device, but the lead frame 2 ispreferably made, for example, of a material which has a relatively greatthermal conductivity. Forming with such a material allows the heatgenerated by the light emitting element 4 to be dissipated moreefficiently. For example, a material having a thermal conductivity ofabout 200 W/(m·K) or greater, a material having relatively highmechanical strength, and/or a material capable of facilitatingoperations in punching-pressing or etching, is preferably employed.Examples of the material include a metal such as copper, aluminum, gold,silver, tungsten, iron, nickel, or an iron-nickel alloy, phosphorbronze, copper-iron alloy, or those materials with a metal plated layerof silver, aluminum, copper, gold, etc., provided on the surface. Thelead frame 2 preferably has a smooth surface to improve the reflectance.The lead frame 2 generally has a uniform thickness, but a thick or thinportion may also be provided.

The overall lead frame 2 is necessary, in one example embodiment, to bemade of a metal or an alloy. There also have been light emitting devicesin use (for example a Chip On Board (COB) type), in which a wiringpattern is applied by way of metal plating on a surface of anon-electrically conductive member such as a ceramics, and a lightemitting element is mounted on the plated metal. However, in such astructure, the light emitting element is disposed over the ceramics,etc, via the plated metal, so that heat generated from the lightemitting element is difficult to transmit to the mounting substrateefficiently. On the other hand, as described above, in the case wherethe entirety of the lead frame 2 is made of a metal or an alloy, due toa high heat conductive property of the metal or alloy, heat generatedfrom the light emitting element 4 can be efficiently transmitted to themounting substrate through the lead frame 2. Thus, compared to thestructure in which a light emitting element is mounted on a ceramic,etc., as described above, more heat can be released from the lightemitting element and therefore the light emitting element can beoperated stably, which also contributes to a longer operational life.

In the light emitting device 1 according to example embodiments of thepresent invention, it is preferable that the lead frame 2 has a planarshape and of the back-surface of the first lead 11, a region directlyunder the light emitting element 4 is exposed. As described above, thelead frame 2 has a planar shape which allows efficient transfer of heatgenerated at the light emitting element 4 which is mounted on the firstlead 11 of the lead frame 2 through the first lead 11 to the mountingsubstrate which is located under the first lead 11. Thus, heatdissipation properties of the light emitting device 1 can be improved.Also, of the back-surface of the first lead 11, a region directly underthe light emitting element 4 is exposed. Thus, heat generated at thelight emitting element 4 can be efficiently transferred to the mountingsubstrate through the exposed region, and in a similar manner as thatdescribed above, heat dissipation properties of the light emittingdevice 1 can be improved. Thus, the lead frame 2 has a planar shape andof the back-surface of the first lead 11, a region directly under thelight emitting element 4 is exposed, which allows for provision of thelight emitting device 1 with good heat dissipation properties.

Bonding Wire

Generally, a bonding wire 8 is used to electrically connect the leadframe 2 and the light emitting element 4, etc. The bonding wire 8preferably has a good ohmic contact or a good mechanical contact with anelectrode of the semiconductor element 4, or has a good electricconductivity and thermal conductivity. The thermal conductivity ispreferably about 0.01 cal/S·cm²·° C./cm or higher, and more preferablyabout 0.5 cal/S·/cm²·° C./cm or higher. In view of workability, thediameter of the bonding wire 8 is preferably, for example, about 10 μmto about 45 μm. Examples of the material for such bonding wire 8 includea metal such as gold, silver, copper, platinum, and aluminum, and analloy thereof.

In the light emitting device 1 according to example embodiments of thepresent invention, the bonding wire 8 which connects the light emittingelement 4 and the first lead 11 is connected to the first lead 11 at aninner side of the resin frame 3 or in the resin frame withoutpenetrating the resin frame 3. On the other hand, the bonding wire 8which connects the light emitting element 4 and the second lead 12penetrates through the resin frame 3 and is connected to the second lead12 at the outside of the resin frame 3. A sealing resin is filled in theinner side of the resin frame 3 to form the first sealing resin 5. Thusthe bonding wire which connects the light emitting element 4 and thefirst lead 11 can be protected with the first sealing resin 5. Further,the bonding wire 8 which connects the light emitting element 4 and thesecond lead 12 is also protected with the first sealing resin 5 and theresin frame 3, so that the bonding wire 8 can be prevented from beingloaded with an excess stress. In a light emitting device which has alead frame formed in a cup shape, the bonding wire is applied over thecup which may result in cutting of the wire due to the bonding wirebeing in contact with the edge of the cup, but in the light emittingdevice according to example embodiments of the present invention, thebonding wire 8 penetrates through the resin frame 3, so that the bondingwire 8 can be prevented from being cut by contacting the lead frame. Thebonding wire 8 is arranged with respect to the resin frame 3 so that thebonding wire penetrates through the resin frame 3. This arrangement canbe obtained by, as described below, the light emitting element 4 and thelead frame 2 being connected with the bonding wire 8, then, the rawmaterial of the resin frame 3 is discharged over the bonding wire 8 toacross the bonding wire 8, and the raw material is cured.

Light Emitting Element

For the light emitting element 4, any element which is a semiconductorlight emitting element, and so-called light emitting diode can be used.For example, such an element includes, a stacked layer structure whichincludes a light emitting layer formed on a substrate, a nitridesemiconductor such as InN, AlN, GaN, InGaN, AlGaN, InGaAlN, a groupIII-V compound semiconductor, a group II-VI compound semiconductor orthe like.

The emission wavelength of the light emitting element 4 can be changedfrom ultraviolet region to red, by changing, for example, the materialsof the semiconductor, the ratio of mixed crystal, the content of indiumin InGaN in the light emitting layer, and kinds of impurity which isdoped in the light emitting layer.

Such a light emitting element 4 is mounted on the upper surface (firstmain surface) 10 of the lead frame 2. In mounting the light emittingelement 4 on the upper surface 10 of the lead frame 2, generally, abonding member is used. For example, in the case of a light emittingelement which is constituted with a nitride semiconductor grown on asapphire substrate and the light emitting element emits blue to greenlight, an epoxy resin, a silicone, etc., can be used. Without the use ofa resin, a solder material such as Au—Sn eutectic, a brazing materialsuch as a low melting point metal may be used. Further, as in ared-emitting light emitting element made of GaAs, etc., a light emittingelement having electrodes formed on the both sides, die-bonding may beemployed with using a conductive paste such as silver, gold, orpalladium. The back-surface of the light emitting element 4 may, forexample, be Al-plated.

In the light emitting device 1 according to example embodiments of thepresent invention, either only a single light emitting element 4 or twoor more light emitting elements 4 may be mounted. In the case where aplurality of light emitting elements 4 are mounted, the light emittingelements 4 may be arranged in a square configuration or in otherconfigurations. Mounting the light emitting elements 4 in a squareconfiguration allows a uniform amount of a fluorescent material betweenthe light emitting elements 4, which allows a reduction in irregulardistribution of emission color.

Also, the light emitting element 4 may be mounted on the lead frame 2via a support member (submount). For example, a support member employinga ceramics may be obtained by forming a predetermined shape and thenconducting calcination. The upper surface side of the support member maybe provided with a conductive wiring which is to be connected to thelight emitting element 4. The conductive wiring is, generally, formed byusing vapor deposition or sputtering technology, a photolithographyprocess, or by using printing technology, etc., or electrolytic plating,etc. The conductive wiring may be provided in the support member. Theconductive wiring is, for example, formed with a material in a pastestate of a resin binder containing a high melting point metal such astungsten and molybdenum. With the use of technology such as screenprinting, the material in a paste state may be applied on the surface ofa green sheet with filling the through-holes defined in the green sheet,then, firing is performed, and thus, the support member made of ceramicsand the conductive wiring arranged on the surface or inside the supportmember may be formed. The support member may be formed by way of insertmolding of a resin, with the use of a pair of positive and negativeelectrodes as the conductive member. A light emitting element 4 may bemounted on an upper surface of such a support member, and electricallyconnected to the conductive wiring of the support member. In the casewhere such a support member is used, the conductive wiring of thesupport member may be electrically connected to the lead frame 2 to bedescribed below. In this case, the light emitting element 4 may bemounted in a face-down (flip-chip) manner.

In the light emitting device 1 according to example embodiments of thepresent invention, when the light emitting device 1 is viewed from thelight emitting surface side, in order to avoid sulfurization problems,the solder which bonds to the bonding wire 8 is preferably gold. Thediebonding area for mounting the light emitting element 4 may besilver-plated. Other areas are preferably plated with a metal other thansilver to prevent sulfurization.

(Sealing Resin)

The first sealing resin 5 may be filled in the resin frame 3 to protectthe light emitting element 4. In the light emitting device 1 accordingto example embodiments of the present invention, after mounting thelight emitting element 4 on the lead frame 2, the first sealing resin 5may be arranged in the inner side of the resin frame 3 to cover thelight emitting element 4. The first sealing resin 5 in the resin frame 3preferably has, for example, the same height as the height of the resinframe 3. In the case where the first sealing resin 5 has a height lowerthan the height of the resin frame 3, creep-up of the first sealingresin 5 due to surface tension may occur. As described above, arrangingthe height of the first sealing resin 5 as the same height of the resinframe 3 may allow for prevention of the occurrence of creep-up of thefirst sealing resin 5. But the first sealing resin 5 and the resin frame3 do not necessarily have the same height, and the first sealing resin 5may either be higher or lower than the resin frame 3.

In the light emitting device 1 according to example embodiments of thepresent invention, the first sealing resin 5 has a refractive index ofabout 1.5 to about 1.6 in view of the refractive indices of the sapphiresubstrate (not shown) of the light emitting element 4 and the secondsealing resin 6. With this arrangement, the difference between therefractive index of the first sealing resin 5 and the refractive indexof the sapphire substrate, and the difference between the refractiveindex of the first sealing resin 5 and the refractive index of thesecond sealing resin 6 can be reduced, and the light extractingefficiency of light extracted from the light emitting device 1 can beimproved.

The first sealing resin 5 is preferably, for example, made of a materialwhich can protect the light emitting element 4 from external forces,moisture, or the like, and also can protect the bonding wire 8 whichprovides the connection of the light emitting element 4 and the leadframe 2.

Examples of the first sealing resin 5 include a light transmissive resinhaving good weather resistance such as an epoxy resin, a silicone resin,an acrylic resin, a urea resin, or a combination of those, or glass. Thefirst sealing member 5 is preferably made of the same material andcomposition, etc., as of the second sealing resin 6 to be describedbelow, and a light diffusion material or a fluorescent material may beincluded in the light transmissive member. The use of the same member asin the second sealing member 6 allows for approximately the same thermalexpansion coefficient in the second sealing resin 6 and the firstsealing resin 5, so that impact resistance against the wire which isarranged over both the second sealing resin 6 and the first sealingresin 5 can be improved. Further, the refractive indices can also beapproximately the same, so that loss of light which passes from thefirst sealing resin 5 to the second sealing resin 6 can be prevented andlight extraction efficiency can be improved. The first sealing member 5may be made of different material, different composition, or the like.In the case where moisture is contained in a resin material for thefirst sealing resin 5, the moisture contained in the resin can beremoved by baking at about 100° C. for about 14 hours or more. Thus,steam explosion and/or detachment between the light emitting element 4and the first sealing resin 5 can be prevented. The first sealing resin5 is preferably selected from the materials which have a smalldifference in the thermal expansion coefficient with other members, inview of adhesion between the second sealing member 6 and the firstsealing member 5 affected by the heat generated from the light emittingelement 4.

In the light emitting device 1 according to example embodiments of thepresent invention, the linear expansion coefficient of the first sealingresin 5 is preferably, for example, 200 to 400 ppm/K, and morepreferably about 300 ppm/K. Also, the elastic modulus of the sealingresin which constitutes the first sealing resin 5 is preferably, forexample, 1 to 3 GPa, and more preferably about 2 GPa.

The first sealing resin 5 may contain a light diffusion material or awavelength converting member (fluorescent material) 18. The lightdiffusion material serves to diffuse light, which allows for loweringthe directivity of light from the light emitting element 4, so that viewangle can be increased. The wavelength converting member 18 serves toconvert light from the light emitting element 4, and the wavelength oflight emitted from the light emitting element 4 to outside of the firstsealing resin 5 can be converted. In the cases where the light from thelight emitting element 4 is a visible light of short wavelength withhigh energy, a perylene derivative which is an organic fluorescentmaterial, inorganic fluorescent materials such as ZnCdS:Cu, YAG:Ce,nitrogen containing CaO—Al₂O₃—SiO₂ activated with Eu and/or Cr, or thelike, can be appropriately used. In embodiments of the presentinvention, in the case where a white light to obtain, particularly, withthe use of a YAG:Ce fluorescent material, depending on the content ofthe YAG:Ce fluorescent material, light from a blue light emittingelement and a yellow light which is emitted by the fluorescent materialupon absorbing a part of the light from the blue light emitting elementand converting its wavelength, can generate a desired white light. Thus,a white light can be generated relatively easily with good reliability.Similarly, in the case where nitrogen containing CaO—Al₂O₃—SiO₂fluorescent material activated with Eu and/or Cr is employed, dependingon the content thereof, light from a blue light emitting element and ared light which are complimentary colors, emitted by the fluorescentmaterial upon absorbing a part of the light from the blue light emittingelement, can generate a white light. Thus, a white light can begenerated relatively easily with good reliability.

The wavelength converting member is, as shown in FIG. 1A, FIG. 2A, andFIG. 3, respectively, by a reference numeral 18, deposited in a layer onthe upper surface of the light emitting element 4 and on the uppersurface of the first lead 11 which is at an inner side of the resinframe 3. Arrangement of the wavelength converting member 18 is notlimited on the upper surface of the light emitting element 4 and on theupper surface of the first lead 11 at the inner side of the resin frame3, but may be contained dispersed in the first sealing resin 5.

(Second Sealing Resin)

In the light emitting device 1 according to example embodiments of thepresent invention, the second sealing resin 6 may be formed to cover theresin frame 3 and the first sealing resin 5, and also at the outer sideof the resin frame 3, to respectively cover at least a portion of thefirst lead 11 and at least a portion of the second lead 12 of the leadframe 2.

The shape of the second sealing resin 6 can be selected from variousshapes. Examples of the shape of the second sealing resin 6 include aplate-like shape, an upper surface with a convex lens shape, an uppersurface with a concave lens shape, a Fresnel lens shape, and a convexlens shape with a recess near the center. With such a shape as shownabove, the directional characteristics can be adjusted.

Now, a case where the second sealing member 6 has a lens shape will bedescribed in detail below. As shown in FIG. 1B and FIG. 2B, the secondsealing resin 6 may include a lens portion formed protruding upward in alens shape 16 and a flange portion 17 extending from a lower portion ofthe lens portion 16 outward. With such an arrangement, the secondsealing resin 6 may have a lens portion 16 formed in a lens shape, sothat the lens portion 16 concentrates the light emitted from the lightemitting element 4 and the directivity of the light can be increased.

In the light emitting device 1 according to example embodiments of thepresent invention, an end of the bonding wire 8 which is connected tothe second lead 12 is preferably, for example, arranged in the flangeportion 17. As described above, arranging an end of the bonding wire 8connected to the second lead 12 in the flange portion 17 allows forpreventing breakage of the bonding wire 8. It is thought that a smalleramount of the sealing resin is arranged around the bonding wire 8 in theflange portion 17, so that the bonding wire 8 may be hardly affected bythe influence of thermal expansion. Also, the bonding wire 8 is notarranged in the lens portion 16, so that absorption of light by thebonding wire 8 can be prevented, which allows for an increase of thelight emitting efficiency.

The second sealing resin 6 can be made of any appropriate material whichallows extraction of light. Examples of the material which constitutesthe second sealing resin 6 include a silicone resin and an epoxy resin.

In the light emitting device 1 according to example embodiments of thepresent invention, the radius of the second sealing resin 6 can be anyappropriate size, as long as, for example, at least a part of the firstlead 11 or the second lead 12 can be covered with the second sealingresin 6 at the outside of the resin frame 3. The radius of the secondsealing resin 6 is determined appropriately according to the planardimension of the light emitting portion.

In the light emitting device 1 according to example embodiments of thepresent invention, the refractive index of the second sealing resin 6may be any value as long as, for example, the difference in therefractive index between the first sealing resin 5 and the secondsealing resin 6, and between the second sealing resin 6 and theatmospheric air, are in an appropriate range. The second sealing resin 6preferably has a refractive index, for example, of about 1.41. With therefractive index of the second sealing resin 6 in such a range, thedifference in the refractive index between the first sealing resin 5 andthe second sealing resin 6 can be in an appropriate range and the lightextraction efficiency can be improved.

(Molded Resin)

As shown in FIGS. 1A and 1B, a molded resin 13 may be disposed betweenthe first lead (cathode) 11 and the second lead (anode) 12 which areexample constituting components of the lead frame 2. As shown above, inan embodiment where the molded resin 13 is disposed between the cathode11 and the anode 12, a gap is not formed between the cathode 11 and theanode 12, so that uncured raw material of the resin frame 3, the firstsealing resin 5, and the second sealing resin 6, can be prevented fromflowing out between the cathode 11 and the anode 12. Also, in such astructure, the resin frame 3 may be formed on the boundary between themolded resin 13 and the first lead 11 or the second lead 12, so that theresin frame 3 holds the burr of the molded resin 13, which allows forfurther improvement in the adhesion between the resin frame 3 and thelead frame 2.

(Protective Element)

In the light emitting devices according to example embodiments of thepresent invention, in addition to at least one light emitting element, aprotective element may also be mounted. Either one or two or moreprotective elements may be used. The protective element 7 is notspecifically limited and any known protective elements in the art mayalso be used in the light emitting device 1. Examples of the protectiveelements may include a protective circuit and/or an electrostaticprotective element which can block a reverse electric current uponapplication of reverse voltage to the light emitting element 4, or whichcan block an excess amount of current to the light emitting element 4upon application of an excessive voltage which is higher than theoperation voltage of the light emitting element 4 and higher than thespecified voltage. More specifically, a Zener diode can be used.

In the light emitting device 1 of according to example embodiments ofthe present invention, the protective element 7 may be preferablyarranged outside of the irradiation range of the light emitted from thelight emitting element 4. With this arrangement, absorption of light bythe protective element 7 can be prevented. More specifically, theprotective element 7 may be mounted outside of the resin frame, or maybe mounted so that a part or entirety of the protective element isembedded in the resin frame.

(Other Components)

In the light emitting device 1 according to example embodiments of thepresent invention, in order to efficiently perform extraction of lightfrom the light emitting element 4, various components such as areflection member, an antireflection member, a light diffusion member,etc., may be provided.

As the reflecting member, a plated layer may be formed on the innersurface of the resin frame 3. The plated layer may be made, for example,of one or more than two of silver, aluminum, copper and gold, etc. Theplated layer is preferably constituted, for example, with silver, andthe whole plated layer may be made of silver. With this arrangement, anextremely satisfactory light extraction efficiency can be obtained.

(Method of Manufacturing Light Emitting Device)

Example manufacturing steps of a light emitting device 1 according to anexample embodiment in which a molded resin 13 is arranged between thelead frame components 2, may be described as follows.

FIGS. 4 to 9 are example diagrams illustrating example manufacturingsteps of the light emitting device 1 according to a embodiment in whichthe molded resin 13 is arranged between the lead frame components 2 (thefirst lead 11 and the second lead 12). Now, each example manufacturingstep will be described in detail below.

(I) Preparing Lead Frame

First, the lead frame 2 as shown in FIG. 4 is prepared. The lead frame 2may be composed of a first lead (for example, a cathode) 11 and a secondlead (for example, an anode) 12, and formed in a planar shape. In thepresent embodiment, the cathode 11 may be formed larger than the anode12, and a light emitting element mounting portion 30 on which a lightemitting element 4 to be mounted may be formed on the cathode 11.

(II) Forming Molded Resin

Then, as shown in FIG. 5, a molded resin 13 may be disposed between thecathode 11 and the anode 12. However, the arrangement of the moldedresin 13 is optional, and as described below, the molded resin 13 may(in an example embodiment) not be arranged between the cathode 11 andthe anode 12. In the case where the molded resin 13 to be arranged, asshown in FIG. 5, the molded resin 13 is arranged not only between thecathode 11 and the anode 12, but also may be arranged to surround thelight emitting element mounting portion 30 of the cathode 11. With suchan arrangement, adhesion between the lead frame and the molded resin canbe improved, and at the time of forming the resin frame, the planardimension available for the formation at the interface between the leadframe and the molded resin can be increased, which allows for animprovement in the adhesion between the resin frame and the lead frame.Also, providing an anchor such as a notch at an end surface of the leadframe may allow for higher adhesion with the molded resin.

(III) Mounting Light Emitting Element and Bonding Wire

As shown in FIG. 6, the light emitting element 4 may be mounted on thelight emitting element mounting portion 30 of the cathode 11. Atmounting, a bonding member such as an epoxy resin, or a silicone resinas described above, may be used. Then, the light emitting element 4 andthe cathode 11 or the anode 12 may be connected with a bonding wire 8.

(IV) Forming Resin Frame

Next, as shown in FIG. 7, a raw material of the resin frame 3 issupplied on the cathode 11 to surround the light emitting element 4, toform the frame and may then be cured. At this stage, the resin frame 3may be formed so that the lower end of the inner surface 20 of the resinframe 3 may be arranged only on the first lead (cathode) 11. Preferably,at the time of forming an uncured frame, a dispenser device which candischarge the raw material of the resin frame 3, for example asyringe-like dispenser (not shown), is moved while discharging the rawmaterial from the dispenser. The amount of the raw material can beadjusted at predetermined locations, so that the thickness and theheight of the resin frame 3 can be changed to desired values.

(V) Forming First Sealing Resin

As shown in FIG. 8, a sealing resin may be filled in the resin frame 3and cured to form the first sealing resin 5. As described above, thefirst sealing resin 5 may contain a fluorescent material or the like,for example.

(VI) Forming Second Sealing Resin

As shown in FIG. 9, the second sealing resin 6 may be formed so that thesecond sealing resin 6 covers the resin frame 3 and the first sealingresin 5, while respectively covering at least a part of the first lead(cathode) 11 and at least a part of the second lead (anode) 12 atoutside of the resin frame 3. The second sealing resin 6 is, forexample, formed by way of transfer molding. First, on the lead frame 2,an upper mold defining a cavity corresponding to the shape of the secondsealing resin 6 (for example a lens shape) may be arranged so that theresin frame 3 and the first sealing resin 5 may be covered with theportion of the mold which defines the cavity, and the lower mold may bearranged to cover the surface of the lead frame 2 where the resin frame3 and the first sealing resin 5 are not formed. In this stage where themolds are placed, the end the portion of the mold where the cavity isdefined may be arranged at outer side of the resin frame 3 so that theresin frame 3 does not come in contact with the portion of the uppermold which defines the cavity. Then, uncured raw material whichconstitutes the second sealing member 6 may be poured into the cavity,and then cured. According to the example manufacturing steps describedabove, the light emitting device 1 in which the second sealing resin 6is formed so that the second sealing resin 6 covers the resin frame 3and the first sealing resin 5, while respectively covering at least apart of the first lead (cathode) 11 and at least a part of the secondlead (anode) 12 at outside of the resin frame 3, can be produced.

Further example manufacturing steps of a light emitting device 1according to an example embodiment in which a molded resin 13 is notarranged between the constituting components of the lead frame 2, may bedescribed as follows.

FIGS. 10 to 14 are example diagrams illustrating example manufacturingsteps of the light emitting device 1 according to an example embodimentin which the molded resin 13 is not arranged between the constitutingcomponents of the lead frame (the first lead 11 and the second lead 12).

Now, each example manufacturing step will be described in detail below.

(I) Preparing Lead Frame

First, the example lead frame 2 as shown in FIG. 10 is prepared. In thepresent embodiment, the resin frame 3 may be formed so that the lowerends of the inner surface 20 and the outer surface 21 of the resin frame3 are arranged only on the first lead (cathode) 11. As shown in FIG. 10,the cathode 11 may be formed larger than the anode 12, and a lightemitting element mounting portion 30 on which a light emitting element 4may be disposed, may be formed on the cathode 11. Also, providing ananchor such as a notch at an end surface of the lead frame may allow forhigher adhesion with the second sealing resin to be described below.

(II) Mounting Light Emitting Element and Bonding Wire

As shown in FIG. 11, the light emitting element 4 may be mounted on thelight emitting element mounting portion 30 of the cathode 11. Atmounting, a bonding member such as an epoxy resin, or a silicone resinas described above, may be used. Then, the light emitting element 4 andthe cathode 11 or the anode 12 may be connected with a bonding wire 8.

(III) Forming Resin Frame

Next, as shown in FIG. 12, a raw material of the resin frame 3 may besupplied on the cathode 11 to surround the light emitting element 4, toform an uncured frame with the raw material of the resin frame 3. In thepresent embodiment, the molded resin 13 is not disposed between thecathode 11 and the anode 12, so that uncured frame may flow out frombetween the cathode 11 and the anode 12. Thus, an uncured frame isformed only on the cathode 11. That is, the uncured frame may be formedso that both the lower ends of the inner surface 20 and the outersurface 21 of the resin frame 3 are arranged only on the first lead(cathode) 11. Then, the frame may be cured to obtain the resin frame 3.

(IV) Forming First Sealing Resin

As shown in FIG. 13, a sealing resin may be filled in the resin frame 3and cured to form the first sealing resin 5.

(V) Forming Second Sealing Resin

As shown in FIG. 14, in a similar manner as described above, the secondsealing resin 6 may be formed so that the second sealing resin 6 coversthe resin frame 3 and the first sealing resin 5, while respectivelycovering at least a part of the first lead and at least a part of thesecond lead 12 at outside of the resin frame 3.

Now, example embodiments of the present invention will be explained indetail below with reference to illustrative examples.

Illustrative Example 1

FIG. 9 shows an example light emitting device 1 having one lightemitting element 4 and a molded resin 13 arranged between the cathode 11and the anode 12 which constitute the lead frame 2. The lead frame 2 hasa cathode 11 and the anode 12 each having a shape as shown in FIG. 4.The cathode 11 is formed larger than the anode 12 and the light emittingelement 4 is mounted on the cathode 11. The lead frame 2 is made of aclad material which is a stacked layer of an alloy of Fe and Cu, anInvar (registered trademark, an alloy made of iron and 36% nickel), andan alloy of Fe and Cu. Then, Ni, Pd, and Au may be plated in this orderfrom the bottom on the surfaces of the lead frame 2. Further, in orderto increase the reflectance of the light emitting portion of the leadframe 2, a plating of Ag may be applied on the Au.

First, as shown in example FIG. 5, the molded resin 13 is disposedbetween the cathode 11 and the anode 12, and around the cathode 11 andaround the anode 12. For the molded resin 13, a polyphthalamide (PPA)resin (an Amodel (registered trademark) in a black color) may be used.An uncured PPA resin may be arranged between the cathode 11 and theanode 12, and around the cathode 11 and around the anode 12, and then,the PPA resin may be cured to form the molded resin 13 having an exampleshape as shown in FIG. 5. The molded resin 13 may be arranged atlocations so as not to be affected by the light from the light emittingelement, so that a material of high reflectance is not needed to beemployed.

Next, one light emitting element 4 may be mounted on the cathode 11. Atthe time of mounting the light emitting element 4 on the cathode 11, abonding material (AuSn) may be used. An AuSn layer may be attached tothe lower surface of the light emitting element 4 and may be melted witha flux coating applied on the metal (cathode 11) to bond. For the lightemitting element 4, a blue light emitting LED may be used. The lightemitting element 4 may have a square shape with an example side of 450μm. Also, for the protective element 7, a Zener diode may be used, andone Zener diode may be mounted on the cathode 11. At the time ofmounting the Zener diode on the cathode 11, an Ag paste may be used.

Then, using the bonding wires 8, as shown in example FIG. 6, the lightemitting element 4 and the protective element 7 may be respectivelyelectrically connected to the cathode 11 and the anode 12. For thebonding wires 8, an Au wire with a diameter of 25 μm may be used.

After wire bonding, a silicone resin which contains titanium oxide maybe formed in a circular shape in a top view, and then cured to form theresin frame 3. The resin frame 3 may be formed so that the resin frame 3surrounds one light emitting element 4, and also the protective element7 may be arranged in the inner side of the resin frame 3. First, thelower portion of the resin frame may be formed so that the resin frame 3has a cross-sectional shape as shown in FIG. 3, and successively theupper portion of the resin frame may be formed with a diameter slightlysmaller than the diameter of the lower resin frame, and then, curing maybe conducted. Thus, the resin frame 3 may be formed.

Subsequently, a silicone resin which contains a fluorescent material(YAG, LAG, and/or SCASN) and a light diffusion material may be injectedto the inner side of the resin frame 3 and cured. Thus, the firstsealing resin 5 is formed. Thereafter, the second sealing resin 6 whichemploys a silicone resin may be formed in a lens shape by way oftransfer molding. First, on the lead frame 2, an upper mold defining acavity corresponding to the shape of the second sealing resin 6 may bearranged so that the resin frame 3 and the first sealing resin 5 arecovered with the portion of the mold which defines the cavity, and thelower mold may be arranged to cover the surface of the lead frame 2where the resin frame 3 and the first sealing resin 5 are not formed.Then, as the second sealing member 6, a silicone resin may be pouredinto the cavity, and then cured.

As described above the light emitting device 1, such as shown in FIG. 9,which has one light emitting element and the molded resin 13 arrangedbetween the cathode 11 and the anode 12 is produced. The light emittingdevice 1 according to Illustrative Example 1 includes a frame to whichthe first sealing resin 5 to be injected is made of a resin, whichprovides high flexibility, and also, the back-surface of the lead frameis exposed, thus good heat dissipating properties is observed.

Illustrative Example 2

FIG. 14 shows an example embodiment of a light emitting device 1 havingone light emitting element 4, and a molded resin 13 is not arrangedbetween the cathode 11 and the anode 12. The light emitting deviceaccording to Illustrative Example 2 has a similar configuration as inIllustrative Example 1, except that in Illustrative Example 1, themolded member 13 is arranged but in Illustrative Example 2, the moldedresin 13 is not arranged.

The cathode 11 and the anode 12 each having a shape as shown in FIG. 10may be prepared. Then, without forming the molded resin 13 between thecathode 11 and the anode 12, one light emitting element may be mountedon the cathode 11. After the above, the light emitting device may bemanufactured in a similar manner as in Illustrative Example 1. In thelight emitting device 1 according to Illustrative Example 2, the moldedresin 13 is not provided and the resin frame 3 is formed only on thecathode 11, so that as described above, detachment of the resin frame 3hardly occurs.

Illustrative Example 3

FIG. 15 shows an example embodiment of a light emitting device 1 having,for example, nine light emitting elements 4 and the molded resin 13 isarranged between the cathode 11 and the anode 12. The light emittingdevice according to Illustrative Example 3 has a similar configurationas in Illustrative Example 1, except that in Illustrative Example 1, onelight emitting element 4 is mounted, but in Illustrative Example 3, ninelight emitting elements 4 are mounted in a matrix shape. Implementationsof the invention are not limited to such numbers of light emittingelements, i.e., any number of light emitting elements may be included.

The cathode 11 and the anode 12 each having a shape as shown in FIG. 4may be prepared, and in a similar manner as in Illustrative Example 1,the molded resin 13 may be formed between the cathode 11 and the anode12. Then, nine light emitting elements 4 are disposed in a matrix shape,and as shown in FIG. 15, using the bonding wires 8, the nine lightemitting elements 4 may be respectively connected to the cathode 11 andthe anode 12. After the above, the light emitting device may bemanufactured in a similar manner as in Illustrative Example 1.

Illustrative Example 4

FIG. 16 shows an example embodiment of a light emitting device 1 having,for example, nine light emitting elements 4, and a molded resin 13 isnot arranged between the cathode 11 and the anode 12. The light emittingdevice according to Illustrative Example 4 has a similar configurationas in Illustrative Example 2, except that in Illustrative Example 2, onelight emitting element 4 is mounted, but in Illustrative Example 4, ninelight emitting elements 4 are mounted in a matrix shape. Implementationsof the invention are not limited to such numbers of light emittingelements, i.e., any number of light emitting elements may be included.

The cathode 11 and the anode 12 each having a shape as shown in FIG. 10may be prepared, and subsequently, without forming the molded resin 13between the cathode 11 and the anode 12, nine light emitting elements 4may be arranged in a matrix shape on the cathode 11. Then, as shown inFIG. 16, using the bonding wires 8, the nine light emitting elements 4may be respectively connected to the cathode 11 and the anode 12. Afterthe above, the light emitting device may be manufactured in a similarmanner as in Illustrative Example 2. As illustrated above, exampleembodiments are described to give a concrete form to technical ideas ofa method of manufacturing light emitting element according to thepresent invention, the present invention is not limited to the describedembodiments of the present invention. Also, obviously, numerousmodifications and variations of the present invention are possible inlight of the above teachings, which are within the scope and spirit ofthe invention, and such other modifications and variations are intendedto be covered by the following claims.

What is claimed is:
 1. A light emitting device comprising: a planar lead frame having a first lead and a second lead, each of the first and second leads having an upper surface, a lower surface, and lateral surfaces; a molded resin located between the first lead and the second lead such that lateral surfaces of the first and second leads face the molded resin, a light emitting element mounted on the upper surface of the first lead; a resin frame surrounding a periphery of the light emitting element; a first sealing resin filled in an inner side of the resin frame and sealing the light emitting element; and a bonding wire connecting the light emitting element with the second lead, at least a part of the bonding wire being embedded in the resin frame, wherein an area below the light emitting element of the lower surface of the first lead is exposed from the molded resin, wherein, in a plan view, the first lead includes a broad portion, a terminal portion, and a narrow portion connecting the broad portion to the terminal portion, a width of the narrow portion being smaller than a width of the broad portion and a width of the terminal portion, wherein the light emitting element is mounted on the broad portion, wherein the molded resin extends around a lateral surface of the broad portion so as to reach lateral surfaces of the narrow portion and the terminal portion, and wherein a lower end of an outer surface of the resin frame is arranged on the narrow portion and the molded resin.
 2. The light emitting device according to claim 1, wherein the resin frame is formed on the molded resin.
 3. The light emitting device according to claim 1, wherein the first sealing resin contains a wavelength converting member.
 4. The light emitting device according to claim 1, wherein the resin frame is slanted inward.
 5. The light emitting device according to claim 1, wherein a thermal conductivity of the lead frame is about 200 W/(m·K) or more.
 6. The light emitting device according to claim 1, wherein the resin frame contains a reflective member.
 7. The light emitting device according to claim 1, further comprising a protective element embedded in the resin frame.
 8. The light emitting device according to claim 1, further comprising a second sealing resin covering at least a part of the first lead and at least a part of the second lead at an outside of the resin frame.
 9. The light emitting device according to claim 1, wherein the lower surface of the first lead, the lower surface of the second lead, and the lower surface of the molded resin are on the same plane.
 10. The light emitting device according to claim 1, wherein a position of an upper surface of the light emitting element is lower than a position of a top portion of the resin frame. 